Cationically-polymerizable iodonium-based formulations are known in the art. Various means to enhance the shelf-stability of such formulations utilizing particular stabilizers have been taught, however the art has not dealt with reduction of run-away reactions when iodonium-based cationically-polymerizable compositions are exposed in-bulk to actinic radiation.
U.S. Pat. No. 5,973,020 describes tetrakis (pentafluorophenyl) borate tolylcumyliodonium and diacetone mixtures containing amino agent stabilizers. It is suggested that such mixtures provide improved shelf-stability.
WO 2005/070989 A2 teaches the use of organic phosphorous stabilizers and hindered nitroxyl stabilizers in cationically-polymerizable formulations to improve shelf stability.
U.S. Pat. No. 6,649,259 B1 discloses a cationically-polymerizable iodonium-based epoxy composition containing a hindered phenol antioxidant. The composition is used as an adhesive coating on a heat-shrinkable polymer film.
Although previously disclosed stabilizers may be useful in improving shelf-life stability, such stabilizers are often of sufficient basicity to reduce cure speeds in cure sensitive cationic applications and to limit continued dark-reaction cationic cure in applications such as stereolithography.